CVE-2026-21870

The record

BACnet Protocol Stack library provides a BACnet application layer, network layer and media access (MAC) layer communications services. In 1.4.2, 1.5.0.rc2, and earlier, an off-by-one stack-based buffer overflow in the ubasic interpreter causes a crash (SIGABRT) when processing string literals longer than the buffer limit. The tokenizer_string function in src/bacnet/basic/program/ubasic/tokenizer.c incorrectly handles null termination for maximum-length strings. It writes a null byte to dest[40] when the buffer size is only 40 (indices 0-39), triggering a stack overflow.

Affected packages

Related vulnerabilities

• CVE-2026-42618 In NTFS-3G before 2026.7.7, a heap buffer overflow exists in ntfs_decompress() in… CWE-193
• CVE-2026-106584 In ssh-keygen in OpenSSH before 10.6, certificates could have incorrect expiration times… CWE-193
• CVE-2026-90781 alsa-lib through 1.2.16.1 contains a stack buffer overflow in the… CWE-193
• CVE-2026-86297 A vulnerability was identified in D-Link DIR-605 B1v202WWB03. CWE-193
• CVE-2026-81738 OpenVPN 2.5.0 through 2.7.6 on Windows using the tap-windows6 driver allows attackers to… CWE-193
• CVE-2026-57160 PJSIP is a free and open source multimedia communication library written in C. CWE-193
• CVE-2026-17469 IBM i 7.6, 7.5, 7.4, and 7.3 could allow a local authenticated attacker to cause a denial… CWE-193
• CVE-2026-14368 The LwM2M JSON content formatter's get_string() in subsys/net/lib/lwm2m/lwm2m_rw_json.c… CWE-193